Interesting...
Do we have to kill Ra-Den, or defeat just like Alganon?

dont know yet. im actually hoping we dont since he could give us some more info on titans and old gods and whatnot. although another part of me hopes he says something like "you are all wrong this planet is wrong the titans will decimate you when they find out about this systemic corruption" or something like that confirming my beliefs that the titans will be villains.

"I was a normal baby for 30 seconds, then ninjas stole my mamma" - Deadpool
"so what do we do?" "well jack, you stand there and say 'gee rocket raccoon I'm so glad you brought that Unfeasibly large cannon with you..' and i go like this BRAKKA BRAKKA BRAKKA" - Rocket Raccoon

I'd just like to mention to everyone that none of the Pantheon reside on Azeroth. They are enjoying themselves elsewere in the Twisted Nether.

However they did leave behind Watchers for their installations (Uldum, Ulduar, Uldaman). They also left behind Avatars as well.

would be cool if blizzard could give us some hint about what exactly their doing i mean are they making new worlds? are they fighting the other old gods in space? do they even know about sargeras yet?

"I was a normal baby for 30 seconds, then ninjas stole my mamma" - Deadpool
"so what do we do?" "well jack, you stand there and say 'gee rocket raccoon I'm so glad you brought that Unfeasibly large cannon with you..' and i go like this BRAKKA BRAKKA BRAKKA" - Rocket Raccoon

I think, and hope we will not kill tyr. So we can get some more titan lore. And he is not Tyr. Tyr was in northen. Pandaria is on the other side of the kontinent.
Ra-Den could many be captured by the horde, so garrosh is going to go all Mogu, by doing the same, by captureing him and stealing his blood to weapons or exepeirments.

dont know yet. im actually hoping we dont since he could give us some more info on titans and old gods and whatnot. although another part of me hopes he says something like "you are all wrong this planet is wrong the titans will decimate you when they find out about this systemic corruption" or something like that confirming my beliefs that the titans will be villains.

Or have Algalon make a return, and help us with this guy. If we aren't killing him maybe we have to defeat shit loads of the golems powered by his blood and try to return it to his body to empower him.

I think, and hope we will not kill tyr. So we can get some more titan lore. And he is not Tyr. Tyr was in northen. Pandaria is on the other side of the kontinent.
Ra-Den could many be captured by the horde, so garrosh is going to go all Mogu, by doing the same, by captureing him and stealing his blood to weapons or exepeirments.

wouldnt be the first time a hellscream used another creatures blood for power

"I was a normal baby for 30 seconds, then ninjas stole my mamma" - Deadpool
"so what do we do?" "well jack, you stand there and say 'gee rocket raccoon I'm so glad you brought that Unfeasibly large cannon with you..' and i go like this BRAKKA BRAKKA BRAKKA" - Rocket Raccoon

would be cool if blizzard could give us some hint about what exactly their doing i mean are they making new worlds? are they fighting the other old gods in space? do they even know about sargeras yet?

There are other worlds we know it for sure.
Quote from AskDev3

As for the wonderfully unique Med'an, no one has seen hide, nor hair of him following Maraad’s return to the Exodar, leading some to believe that he has traveled to a new world or plane to continue his training.

Argus, the homeworld of the eredar race of magic-wielders and their exiled brethren called the draenei.
Azeroth, the world where most of the action of the Warcraft universe is set.
K'aresh, the original homeworld of the ethereals before they evacuated to wander the Twisting Nether.
Draenor (Outland) was the homeworld of the orcs, ogres, and other species, and a sanctuary of the draenei. It was destroyed in a cataclysm. The remains of Draenor have become the extradimensional realm of Outland.[1]
Xoroth, the homeworld of the dreadsteeds (and possibly the nathrezim and tothrezim)
Fanlin'Deskor, a world annihilated by the Burning Legion.
We know that there's great dark beyond and this
Countless other unnamed worlds have been visited by the titans, the naaru, and taken over or obliterated by the Burning Legion.
This gives me chills
At least seven planets are set to feature in future patches and/or expansions for World of Warcraft, courtesy of Outland's Dimensional Gateways.
+http://www.wowpedia.org/Great_Dark_Beyond
So this "world" lore can be expanded and Titan can become villians or more strong guys can appear then titans. Other wolds should have other "kings"

But i do belive he was the one wather who used to control the mogu, since acoring to their history, the ate his heart, and you can see on the picture his chest are open, So he have probaly ever since that just been hold as a prisonoer. But i hope he have not gone 100% insane. even though after so many years, all he want is to die, or do some mindless killing

but the pandas defeated the guy who killed a watcher by himself and ate his heart gaining his powers. and they did it with dances and no weapons O-O

sure the jinyu were talking to water and the grummles were letting them borrow their luckydos and the hozen were diggin them tunnels so they could ook them in the dooker from behind.

but still the pandaren beat them with no weapons and just funny dances! .... okay it was mostly the luckydos BUT THE FUNNY DANCES WERE IMPORTANT @_@

"I was a normal baby for 30 seconds, then ninjas stole my mamma" - Deadpool
"so what do we do?" "well jack, you stand there and say 'gee rocket raccoon I'm so glad you brought that Unfeasibly large cannon with you..' and i go like this BRAKKA BRAKKA BRAKKA" - Rocket Raccoon

I'm just hoping this bastard is the size of Kologarn. Really though, how could he be alive with so much blood taken out for golems and weapons unless he was just that big and had that much blood. Just let it be bizarro Kologarn where we heal each body part instead of destroying it.

I'm just hoping this bastard is the size of Kologarn. Really though, how could he be alive with so much blood taken out for golems and weapons unless he was just that big and had that much blood. Just let it be bizarro Kologarn where we heal each body part instead of destroying it.

maybe titan constructs heal really fast kinda like wolverine. thus all the cuts required to slow down his healing factor

"I was a normal baby for 30 seconds, then ninjas stole my mamma" - Deadpool
"so what do we do?" "well jack, you stand there and say 'gee rocket raccoon I'm so glad you brought that Unfeasibly large cannon with you..' and i go like this BRAKKA BRAKKA BRAKKA" - Rocket Raccoon

We don't even know if the titan is a boss though. The shackles kinda make it seem like he is being imprisoned. Maybe he is just a titan watcher that has been captured by the thunder king and the thunder king has been using his blood to fuel the machines and weapons that seem to have his blood in them.

Could possibly be that we are saving this titan watcher from an army of blood machine things

Please, not another Madness of Deathwing where its just a gauntlet event with a lot of blood, not right for an end boss of a tier to not fight the boss, but just adds.

Ra-Den (Watcher: Vale of Eternal Blossoms) <-- Theorized
Think this is more or less accurate.

I think he's been rather the Keeper of the Titan Complex of Pandaria (Now called Mogu'shan Vaults).

Too often, we are mistaken for druidic types. perhaps that's true for some shaman, but do not let yourself be plagued by the ignorant belief that we are always peaceful.
Nothing about what I do is harmonious. I command the elements to my will. There is nothing offered in return. I would have it no other way.